Dangnabit... now I don't know what to think! I tried spraying some starter fluid around the intake boots (rubber bits between the cylinder intake and carb) and nothing - no change at all - so I'm not sure it's a vacuum leak after all. They seemed perfect when I put them on, with no visible damage anywhere, so maybe I just didn't seat it good enough. I will need to verify that.
But I'm leaning more and more to something still being wonky in the pilot circuit like suggested. It seems like it's just the left side carb that is acting up. I know one of the carbs was a bit more munged up than the other and harder to clean out, and I believe it was the left side. Kind of makes sense, as that would be the one with fuel left in it longer with the bike leaning over to the left on its side stand.
The pilot jets in particular were really hosed up. I had thought about replacing them (Keihin p/n N424-24B-42) when I had everything apart, and now really wish I had.
I still haven't tried disconnecting the TPS or messing with it at all... does any of this sound like something that it could be causing?
